Infrared thermometers can be used for the diagnostic and predictive inspection of electrical equipment and systems. Heat is generated by electrical currents and one of the most efficient methods of predicting the potential failure of equipment is via temperature monitoring. Users can quickly get information about temperature by making use of an infrared thermometer.
Precise readings with between 0.75 to 2% accuracy can be provided by infrared thermometers from a distance of as much as 35 feet, depending on the particular model. An infrared thermometer requires no setup and come with a response time of under a second. They are also easy to use, lightweight and very durable.
How to measure electrical components with infrared thermometers
Contactless infrared thermometers are able to measure an object’s surface temperature from a distance, and can do so with such accuracy only for a directly visible target. This means that the likes of enclosures and covers have to be removed so that the object is fully exposed to allow the infrared thermometer to measure it.
Motors and circuit breakers and transformers are able to be directly measured due to the fact that their enclosures’ surface temperatures are normally correlated to the internal temperature. There are several applications that can be involved in a comprehensive maintenance program designed to prevent unscheduled downtime caused by equipment failures.
Connectors
Environmental temperature changes and even normal on/off current loading can cause the repeated expansion and contraction of connections and result in the gradual loosening of the connector. A loose connector will be more resistant to the flow of current, dissipating power and resulting in the generation of heat. Higher resistance can also be caused by carbon deposits, connection corrosion and dirt.
Knowing the difference in temperature between the ambient temperature and the connector is crucial to the successful evaluation of connectors. The contactless thermometer can quickly determine the ambient temperature and temperature increases that are more than 10 degrees C over it indicate an unbalanced load, bad connection or ground in circuit. A temperature reading of more than 30 degrees C above means there is a serious problem.
Electric motors
Hundreds of polyphase motors are often in operation in industrial plants and to ensure their long lifespan temperatures have to be monitored for the purpose of verifying correct operating temperatures and phase to phase power distribution.
Motor bearings
The breakdown of bearings generates heat, resulting in the motor vibrating and becoming off-centre. Using an infrared thermometer to scan bearing temperatures can detect hot spots, allowing for replacements or repairs to be scheduled before equipment failure happens.
Transformers
A transformer usually lists the maximum operating temperature that is permissible for it, and an infrared thermometer can directly measure the windings of air-cooled units in order to verify the overall temperature. If any hot spots are discovered this is an indication of winding flaws.
Ballasts
Lighting fixtures can sometimes overload due to aging electrical components and overheated ballasts can be detected by an infrared thermometer before they start smoking.
Other electrical applications for infrared thermometers include utilities, backup batteries, uninterruptible power supplies, cables and wires and phase-to-phase measurement.
